Pellets from Pine Needles?

Joined: Jun 08, 2011
Posts: 6

posted Jun 08, 2011 17:13:21

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I live in, believe it or not, a pine forest in Nicaragua. While our primary energy source is PV solar, we end up running a backup generator at times during the rainy season. I have been looking at the GEK Gasifier to convert something such as tree and coffee plant trimmings into gas to run a generator.

Our biggest currently wasted resource and, in the dry season, fire danger are pine needles. With the majority of 143 manzanas (about 265 acres) covered with pines I don't think we will severely damage the forest cycle by using some pine needles for fuel. The trick is how. The pelletizers I have looked at are designed to use sawdust as the input. I would like to find or build something that would work with pine needles.

I am open to suggestions.

Joined: Jun 08, 2011
Posts: 1

posted Jun 08, 2011 23:26:19

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Very interesting idea!

To determine the viability of pine-needles as a fuel source you need 2 pieces of information: Required energy to pulp and form the pine-needles into pellets; and Calories per pound of pine-needles energy yield when burnt.

To measure the energy required to process the pine-needles: Run your machine for a fixed amount of time with a sizable measured quantity of pine-needles. Measure fuel before and after. 5,749.35 kcal energy per gallon of gasoline. (Assuming the engine runs at roughly 20% efficiency)

If energy yield is more than the required energy to process, you have a fuel source. If not, you have a means to store energy.

..and I probably just went off on a tangent regarding your question.

Edit_1: I should add, pine sap burns quite well and is very flammable. Since dry pine-needles contain a good amount of dried sap, they have the potential to store allot more energy than standard wood pellets.

I'm sure you know that pine smoke is rather noxious --should probably take that into account as well. (expect lots of soot/choking smoke)

Around here are oaks and pines. People rake up their yards and put bagged leaves at the street for pickup. I've collected a few hundred bags for use in compost, but have looked at pellet mills to use the stuff as a fuel. It's abundant and free.

For pine needles, a shredder or hammer mill may be needed to pulverize the needles into a suitable size for the mill. Burning pine needles has the same problem as pine firewood-creosote formation within the flue. It can be used, but regular cleaning of the flue will be in order.

I have been looking at pellet mills on-line. There seem to be some inexpensive options, generally from China. The real question is whether any of them can work directly with the pine needles or if a hammermill would also be required. With the number of pine needles in the world, it would seem if the pellet makers can't work with them, someone should make one that would.

Joined: Feb 20, 2011
Posts: 6734
Location: Currently in Seattle. Probably moving 1 hour north by end of the year.

141

posted Jun 12, 2011 15:47:31

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It has been many years since I have used pine as a fuel source, but the green vs dry needles certainly burn differently. I have no clue what the energy output ratio of green:brown needles is, but it would be worth investigating. Well dried needles probably put out less creosote than fresh (as well as less odor). What might be cheaper (and easier to find) than a hammer mill is a common household garbage disposal. If you can convert it into a 'mush', it might be a lot easier to pelletize. That much land in pines should be sufficient to provide a lot of fuel (at the right price).

Watching the video and a couple of others, the brickquet idea. It seems like the total of something to make them into mush and the press is less technology than just a pellet maker. It also offers the option to make different sizes to see what works best in the GEK.

As it will run some sort of IC engine to drive an alternator, I can probably steal some of the engine output to run something to break up the pine needles if needed.

Thanks for the suggestions/pointers. Sounds like the next step is to get the GEK. Note that the GEK is about as experimental as these forums so such things as the success of using pine needles and green vs. brown is the type of stuff that will fit into their forums.

John Polk
steward

Joined: Feb 20, 2011
Posts: 6734
Location: Currently in Seattle. Probably moving 1 hour north by end of the year.

141

posted Jun 12, 2011 22:13:14

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I'm sure that there are plenty of folks on this forum with an abundance of pine needles that would love to hear how your project progresses. Any step towards getting 'function' from 'waste' would be welcome news for anybody involved with PC. Keep us informed on how the experiments are working.

Joined: May 24, 2011
Posts: 35
Location: eastern part of West Tennessee

posted Jun 13, 2011 04:19:33

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With the mush method I don't see as much of a problem, but wet or dry you will get a sap build up on the processor. All equipment need regular cleaning and mantance, but anything dealing with resin/sap more so.

There are too many new and different mistakes out there waiting to be made to be wasteing your time repeating the same old mistakes.

I'm in the middle of the hammer mill pelletizing briquette making fiasco.

I can personally assure you a garbage disposal wont work. I'm very greatfull for return policies, my 1hp garburator jammed up with just a few handfulls of blackberry. The amount of water you have to run through a garburator makes processing the mush really inefficient. I tried sifting the mud to drain off excess water which I needed to flush the garbage disposal but after 5 minutes it would no longer flush. I was using a 3 stage grind anything garbage disposal the top of the line before going commercial. It just doesn't play ball with lignin fibers, they lay flat go round and round and build up till the machine stops. It was hard enough getting them through the woodchipper to bring em down in size.

The problem with briquette making is loading the pvc tube if your not dealing with a pourable slurry, it get's really slow hand stuffing it and makes for irregularly dense briquettes. Pine needles would have enough resin to be your natural binding agent in a briquette press, but the volume you need to process to make the endevour worthwhile just wont flow down a garburator. Life's gone from a 400 dollar solution that didn't work to a 4000 dollar solution that works at way more than just fuel but animal feed aswel.

I recently heard that the principle fuel for heating in Nepal is pelletized pine needles. Tonight I am searching for more info as I live in british columbia where ponderosa pine needles are a fire hazard. They are many inches thick under the trees.Im looking for curious others.

As a pellet mill owner and someone who also shares access to pine, hemlock and spruce fallout.
I don't see any reason why not to other than managing the resin. When that pellet mill starts to heat up and steam things could get really iffy, I would definetly prefer to work with dried material to lean things in the favor of it flowing through the mill happily.
I havn't been pelletizing for long but jam's can get bad if material isn't prepped appropriately for the die size. I've jammed the wood pellet sized die with material that flowed great through the fish food size die and vice versa. When the mill jam's and even worse begins to cool the die's can get really jammed with what is become rock as it cools. If you have access to a mill by virtue of your situations, I'd start with a blend and then work your way up to green vs brown etc. You can go all out and try to work with straight pine but if anything goes wrong you could be out 3 hours taking the mill apart and drilling out your die hole by hole. Sometimes looking to evidence of other people using it doesn't always help if there processing technology is either better researched, more industrial or simply more advanced. A living example I'm in the middle of is living is I don't have enough storage to cool my pellet's to do more than 2 hours worth of pelleting per day, when I hit that wall I fianly saw the value of that terrible cooling conveyor belt contraption that everyone who's in any sort of commercial situation must have.
So if your like me and you just managed to squeeze a hammer and pellet mill into your system, it can be a long ways away in comparison with what I see being pelletized as inspirational as all that bio conversion is. I still have no sensible way to shred a bale of hay efficiently, hand feeding clumps is ridiculous when it comes to efficiency but I'm not trying to go into business doing it so i'll never be able to justify a feed grinder. So my alternative of driving a mulching mower all over an open bale creates a whole other layer of processing and transport that start's to make the energy audit obscene. But if I'm working with wood chips which is a disposal issue in my situation I have no problems I can hammermill and make pellets as fast as I can lift barrels of it with no processing.

So pine for better or worse btu and burn cleanliness, if it's what you got "WORK WITH IT" but remember your learning to work with someone because it's what you got, it won't simply work because everyone else is doing it. They may be doing something rediculous to process it that kills it's sensibility like me with the hay bales that I don't broadcast is actualy a pain in the ass. Life would be different if I was brush cutting it and could dry and bag it easily. I'm sad to say I secretly now dream of a tumbler dryer, no matter how much I know i'll never be able to afford one or justify it's energy audit.

Just a question, but perhaps you are approaching this with the assumption you need to make pellets. Since it is for your own use, you might be able to modify the intake of the GEK to accept dry pine needles instead of pellets. I do believe they have feed system now.

Since pine needles are already uniform in size (which is one of the reasons to make pellets), perhaps you can just feed them directly, slowly. There are systems that burn sawdust directly, so I don't know why you couldn't burn pine needles the same way, all you have to do is solve the feeding problem.

And since you are going to have to solve the feeding problem before you can make pellets efficiently, might as well.

What I would probably do is investigate burning pine needles in gasification, it seems to me that should be the first issue.

I have looked into pellets, I haven't convinced myself yet to take the leap since I would need a market, and how to get it there. Currently, I mainly use it to improve soil, etc.